Rocket propellants



2,933,381 nocrnzr PROPELLANTS Simon L. Ruskin, New York, N.Y., assignorto-Union Carbide Corporation, New York, N.Y., a corporation of New YorkNo Drawing. Application August 27, 1956 Serial No'. 606,205

1 Claim. (Cl. 52-.5)

My invention relates to rocket fuels and the likewhereby the free energystored in organic compounds are burned producing a hot gas and anexplosive impulse capable of propelling a rocket or other device.

While organic compounds have hitherto been employed for such purposes,it has been found that organic. residues tend to form at the jet end. ofthe rocket obstructing the outflow and diminishing the efficiency of thecombustion as well as the propellant. Incomplete utilization of the fuelleads to abortive results in propulsion. A still further difficulty withrocket fuels is that the explosive state of the fuel is highly dangerousto personnel handling the fuel prior to the launching of the rocket.Hitherto it was found that the better the fuel, the greater was theproblem of handling.

I have found that these difficulties may be overcome by reacting aunique preparation, to be described below; and an organic compound. Inthe reaction of this invention, graphitic acid which has been made intopaste with hydrofluoric acid, is combusted by aluminum triethyl or itsanalogues or other spontaneously inflammable metal alkyl or rylcompounds.

One of the ideal reactions desired in a rocket fuel is the interactionof nitrogen, oxygen and fluorine with a possible arrangement of at. F

ifpossible burned with atomic hydrogen. No such compound has hithertobeen attained. I have found that a reaction involving nitrogen, oxygenand fluorine can be catalyzed during explosion of my system ofcompounds. To .prepare my graphitic acid I may use potassium chlorateand nitric acid or potassium chlorate, nitric and sulphuric acid. Whenemploying nitric acid of 90% to 95% (red acid) a green to brown or redcolor results. The graphite is wetted, swells up and disintegrates. Theexcess potassium is evaporated 01f leaving a brownish to reddish massbut evaporation is mild enough not to diminish the increased volumewhich the graphite has assumed. Both oxygen and hydrogen are taken upbetween the aromatic lattice structure of the graphite and an estimatedcomposition of C 0 with water adsorbed on the surface of the colloidalmaterial. The color of the composition may vary with the amount of Wateradsorbed. Between the sheets of the lattice structure of the graphitethere are also trapped nitrate radicals. The insertion of the oxygen andnitrogen atoms between the graphite sheets forces them apart and altersthe spacing to twice or three times the normal 3.4 A. To induce greaterreactivity of the graphite I irradiate the graphite with 100 million R.to 400 million R. by either a cobalt 2,933,381 V Patented Apr. 19, 196060 source, high voltage or neutron flux.

The semi-dry mass is now made into a paste by the addition of a 35%aqueous hydrogen fluoride. The presence of the adsorbed Water on thesurface of the graphite lattice inhibits spontaneous explosion bycombination of the hydrogen fluoride with the carbon.v Either theremoval of the adsorbed water or heat is required to initiate theexplosion. This composite material which I designate graphigen" becomesviolently explosive when aluminum triethyl is added in the presence ofair. Carbon monoxide and dioxide are formed. The reaction then proceedsto the formation of mellitic acid which is completely com busted to COand water. In the intense heat the water is ionized to atomic oxygen andhydrogen. The residue is fine crystallites of graphite which are notadherent to the jet end of the rocket.

The layer of adsorbed water between the lattice structure of thegraphite intensifies the reaction of the aluminum triethyl leading tothecomplete combustion.

To instantaneously trigger the explosion of the alumninum triethyl andthe graphigen I may add a solution of ammonium chloride in liquidammonium thus providing atomic hydrogen according to the followingformula.

nium salts or amides in liquid ammonium.

Example 1 100 grams of finely divided graphite is mixed with 300 gramsof potassium chlorate and sufiicient red acid (90% nitric acid) to givea liquid mass. It is allowed to stand for four to six days. As thenitric acid is absorbed it is renewed four or five times until a yellowred mass results. It is allowed to dry at room temperature. a Whileheating in a water bath hastens the reaction, it may also be conductedat room temperature. The graphigen may be stored in this condition atroom temperature. Before use, the graphigen is soaked in 35% hydrogenfluoride for several hours and the rocket cartridge filled therewith.The aluminum triethyl contained in glass lined jet container sealedunder argon is arranged so that a stream of aluminum triethyl may besprayed on the graphigen simultaneously with a stream of ammoniumchloride in liquid ammonium.

Detonation may be accomplished also by standard methods commonlypracticed in the art.

What I claim is:

A rocket fuel consisting essentially of a mixture of an aqueous solutionof hydrogen fluoride with graphitic acid, said graphitic acid being thepartially dried product of the combination of finely-divided graphitewith an alkali- References Cited in the file of this patent UNITEDSTATES PATENTS Aylsworth Apr. 27, 1915 OTHER REFERENCES Sidgwick:Chemical Elements and Their Compounds, Oxford Univ. Press, London(1950), vol. 1, pp. 494-6.

